How it works?
Google Vector Layers works by listening to map events (pan and zoom) and then fetching features within the map bounds after each event. This method works great for data sets with lots of features that you want to interact with, but not load all at once.

Features:

Multi-Provider Support - Current support for ArcGIS Server, Arc2Earth, Geocommons and CartoDB (with more in mind)

Easy InfoWindow Templating - Create InfoWindow templates with a simple string with property names {mustached} or with a function that gets passed feature properties, and should return valid HTML for the InfoWindow

Dynamic Data Support - Easily visualize live data that auto-updates at an interval that you set (and makes sense for your data’s update frequency)

Simple, Powerful Symbology - Style your layers with
a single symbology, a unique symbol for specific attribute values or
set symbols to display if a feature’s attibutes are within a specific
range. Or …

Use Your Current Styles - If you’re using an ArcGIS Server layer you can use the styles you’ve already spent time creating in ArcMap

Scale Dependent Rendering - You wouldn’t want to show lots of features with complex geometries at lower zoom levels - Using scaleRange lets you set the minimum and maximum scales a layer should be visbible